Organic EL device has many advantages such as self-emitting, wider viewing angles, faster response speeds and highly luminescence. Their simpler fabrication and capable of giving clear display comparable with LCD, making organic EL device an industry display of choice. Organic EL device contain emitting materials which are arranged between a cathode and a anode, when a applied driving voltage is added, an electron and a hole were injected into the emitting layer and recombined to form an exciton. The exciton which results from an electron and a hole recombination have a singlet spin state or triplet spin state. Luminescence from a singlet spin state emits fluorescence and luminescence from triplet spin state emits phosphorescence.
Organic EL device are generally composed of functionally divided organic multi-layers, e.g., hole injection layer (HIL), hole transporting layer (HTL), emitting layer (EML), electron transporting layer (ETL) and electron injection layer (EIL) and so on. A emitting material have good charge carrier mobility and excellent operational durability can lower driving voltage and power consumption, increasing efficiency and half-lifetime of organic EL device.
For full-colored flat panel displays in AMOLED, the compound used for the blue emitting layer are still unsatisfactory in half-lifetime and driving voltage. Many compounds are used for fluorescent blue host in emitting layer. U.S. Pat. No. 5,935,721 used 9,10-di(naphthalen-2-yl) anthracene (AND) as blue host in emitting layer. U.S. Pat. No. 7,691,492 used 1,1-(9,9-dimethyl-9H-fluorene-2,7-diyl)dipyrene (DFDP) as host for blue organic EL device. These compounds still have disadvantages for industrial practice use.
In the present invention, for the purpose to prolong the half-life time and lower driving voltage for fluorescent blue emitting organic EL device, we employ an indenotriphenylene skeleton link to a heteroaryl group substituted naphthyl anthracene group to finish the compound represented as general formula(A). The triphenylene skeleton show good thermal stability and charge carrier mobility for organic EL device. Triphenylene skeleton based derivative disclosed in U.S. Patent No. 2004/0076853, WO2006/130598 and WO2012035962A1 are used for organic EL device are described. There are no prior arts demonstrate such an indenotriphenylene skeleton formula(A) used as fluorescent blue host for organic EL device.